Gunsmithing Barnes 70gr TSX copper fouling, how bad is it?

Chicory01

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Minuteman
Jul 5, 2017
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I've been reading reports of the extreme copper fouling caused by Barnes TSX bullets in rifles. Some people are claiming their groups expanding from 1 MOA to 4-6 MOA after 30 rounds.

There are some articles claiming Barnes has fixed this issue with the introduction of grooves within the bullet to ease fouling and lower the pressure. Does this provide any significant relief of copper fouling or is the difference minimal?

I plan on using the 70gr TSX in a KAC SR15 for self defense and hunting. I'm now unsure if these would be ideal for using mag after mag in a prolonged self defense situation.

Can anyone confirm just how bad these bullets depreciate accuracy after only 1-2 magazines?

Thanks in advance!